Pain accompanies mankind from his birth until the end of his life. Perhaps for this reason, one type of fear, among many which exist, also accompanies man throughout his life, the fear of pain.
In odontological treatment, for example, fear of pain is almost constant, in spite of the fact that the advances in modern dentistry have been able to soothe in an extraordinary way the unpleasant sensations experienced by the patient. Tension and anxiety still remain and constitute factors that discourage many patients from going to the dentist, afraid of the pain they might feel. Fear is the most significant factor among the many reasons given for failure to see a dentist.
The search for solutions to diminish the "stress" of odontological patients has been a concern of dental care providers. The impulse-therapy or transcutaneous nervous electrostimulation, i.e. "ENT" or "TENS", is an efficient method to achieve a physiological, rational and non-invasive relaxation, of specific muscular areas.
In 1975, Bernard Jankelson initiated studies on its applications in the odontological area, and developed a device, the "Myo-Monitor" of specific use in dentistry. Since then, many similar devices have been developed with the same purpose of relaxation and regulation of the musculature of the odontostomatognatic system. All of them utilize low frequency, fixed or variable (from 40 to 350 impulses per minute) to attain the proposed objectives. These devices, in spite of presenting results considered satisfactory, have several restrictions, due, mainly, to the adoption of a unique band of performance of the electrostimulating signals, the most critical being the following:
The high frequency applied separately promotes a fast analgesic and relaxing effect, however of low duration after its application.
The low frequency applied separately promotes analgesic, relaxation of longer duration, after application; however, it takes longer for the effect to initiate and, besides this, it provokes an unpleasant sensation in the patient.
The low frequency can only be utilized up to 300 pulses per minute, for above this it promotes muscular stress, which is a totally undesirable effect.